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Jeong-Hyuck Park

Publications and source records attributed to Jeong-Hyuck Park.

At least 73 records · Page 4Linked to original sources

Symmetries and dynamics in constrained systems

We review in detail the Hamiltonian dynamics for constrained systems. Emphasis is put on the total Hamiltonian system rather than on the extended Hamiltonian system. We provide a systematic analysis of (global and local) symmetries in total Hamiltonian systems. In particular, in analogue to total Hamiltonians, we introduce the notion of total Noether charges. Grassmannian degrees of freedom are also addressed in details.

math-ph↗

Three-algebra for supermembrane and two-algebra for superstring

While string or Yang-Mills theories are based on Lie algebra or two-algebra structure, recent studies indicate that M-theory may require a one higher, three-algebra structure. Here we construct a covariant action for a supermembrane in eleven dimensions, which is invariant under global supersymmetry, local fermionic symmetry and worldvolume diffeomorphism. Our action is classically on-shell equivalent to the celebrated Bergshoeff-Sezgin-Townsend action. However, the novelty is that we spell the action genuinely in terms of Nambu three-brackets: All the derivatives appear through Nambu brackets and hence it manifests the three-algebra structure. Further the double dimensional reduction of our action gives straightforwardly to a type IIA string action featuring two-algebra. Applying the same method, we also construct a covariant action for type IIB superstring, leading directly to the IKKT matrix model.

hep-th↗

Topological Twisting of Multiple M2-brane Theory

Bagger-Lambert-Gustavsson theory with infinite dimensional gauge group has been suggested to describe M5-brane as a condensation of multiple M2-branes. Here we perform a topological twisting of the Bagger-Lambert-Gustavsson theory. The original SO(8) R-symmetry is broken to SO(3)XSO(5), where the former may be interpreted as a diagonal subgroup of the Euclidean M5-brane world-volume symmetry SO(6), while the latter is the isometry of the transverse five directions. Accordingly the resulting action contains an one-form and five scalars as for the bosonic dynamical fields. We further lift the action to a generic curved three manifold. In order to make sure the genuine topological invariance, we construct an off-shell formalism such that the scalar supersymmetry transformations are nilpotent strictly off-shell and independent of the metric of the three manifold. The one loop partition function around a trivial background yields the Ray-Singer torsion. The BPS equation involves an M2-brane charge density given by a Nambu-Goto action defined in an internal three-manifold.

hep-th↗

M-brane bound states and the supersymmetry of BPS solutions in the Bagger-Lambert theory

We continue our study of BPS equations and supersymmetric configurations in the Bagger-Lambert theory. The superalgebra allows three different types of central extensions which correspond to compounds of various M-theory objects: M2-branes, M5-branes, gravity waves and Kaluza-Klein monopoles which intersect or have overlaps with the M2-branes whose dynamics is given by the Bagger-Lambert action. As elementary objects they are all 1/2-BPS, and multiple intersections of $n$-branes generically break the supersymmetry into $1/2^n$, as it is well known. But a particular composite of M-branes can preserve from 1/16 up to 3/4 of the original ${\cal N}=8$ supersymmetries as previously discovered. In this paper we provide the M-theory interpretation for various BPS equations, and also present explicit solutions to some 1/2-BPS equations.

hep-th↗

M-theory on pp-waves with a holomorphic superpotential and its membrane and matrix descriptions

We study a new class of inhomogeneous pp-wave solutions with 8 unbroken supersymmetries in D=11 supergravity. The 9 dimensional transverse space is Euclidean and split into 3 and 6 dimensional subspaces. The solutions have non-constant gauge flux, which are described in terms of an arbitrary holomorphic function of the complexified 6 dimensional space. The supermembrane and matrix theory descriptions are also provided and we identify the relevant supersymmetry transformation rules. The action also arises through a dimensional reduction of N=1, D=4 supersymmetric Yang-Mills theory coupled to 3 gauge adjoint and chiral multiplets, whose interactions are determined by the holomorphic function of the supergravity solution now constituting the superpotential.

hep-th↗

Classification of the BPS states in Bagger-Lambert Theory

We classify, in a group theoretical manner, the BPS configurations in the multiple M2-brane theory recently proposed by Bagger and Lambert. We present three types of BPS equations preserving various fractions of supersymmetries: in the first type we have constant fields and the interactions are purely algebraic in nature; in the second type the equations are invariant under spatial rotation SO(2), and the fields can be time-dependent; in the third class the equations are invariant under boost SO(1,1) and provide the eleven-dimensional generalizations of the Nahm equations. The BPS equations for different number of supersymmetries exhibit the division algebra structures: octonion, quarternion or complex.

hep-th↗

Spacetime Emergence in the Robertson-Walker Universe from a Matrix model

Using a novel, string theory-inspired formalism based on a Hamiltonian constraint, we obtain a conformal mechanical system for the spatially flat four-dimensional Robertson-Walker Universe. Depending on parameter choices, this system describes either a relativistic particle in the Robertson-Walker background, or metric fluctuations of the Robertson-Walker geometry. Moreover we derive a tree-level M-theory matrix model in this time-dependent background. Imposing the Hamiltonian constraint forces the spacetime geometry to be fuzzy near the big bang, while the classical Robertson-Walker geometry emerges as the Universe expands. From our approach we also derive the temperature of the Universe interpolating between the radiation and matter dominated eras.

hep-th↗

Topological twisting of conformal supercharges

Putting a twisted version of N=4 super Yang-Mills on a curved four-dimensional manifold generically breaks all conformal supersymmetries. In the special case where the four-manifold is a cone, we show that exactly two conformal supercharges remain unbroken. We construct an off-shell formulation of the theory such that the two unbroken conformal supercharges combine into a family of topological charges parameterized by CP^1. The resulting theory is topological in the sense that it is independent of the metric on the three-dimensional base of the cone.

hep-th↗

Massive super Yang-Mills quantum mechanics: classification and the relation to supermembrane

We classify the supersymmetric mass deformations of all the super Yang-Mills quantum mechanics, which are obtained by dimensional reductions of minimal super Yang-Mills in spacetime dimensions: ten, six, four, three and two. The resulting actions can be viewed as the matrix descriptions of supermembranes in nontrivial backgrounds of one higher dimensional supergravity theories. We also discuss the utmost generalization of the light-cone formulation of the Nambu-Goto action for a p-brane, including time dependent backgrounds.

hep-th↗

Matrix models for D-particle dynamics and the string/black hole transition

For a generic two-dimensional 0A string background, we map the Dirac-Born-Infeld action to a matrix model. This is achieved using a canonical transformation. The action describes D0-branes in this background, while the matrix model has a potential which encodes all the information of the background geometry. We apply this formalism to specific backgrounds: For Rindler space, we obtain a matrix model with an upside-down quadratic potential, while for AdS_2 space, the potential is linear. Furthermore we analyze the black hole geometry with RR flux. In particular, we show that at the Hagedorn temperature, the resulting matrix model coincides with the one for the linear dilaton background. We interpret this result as a realization of the string/black hole transition.

hep-th↗

Superfield theory and supermatrix model

We study the noncommutative superspace of arbitrary dimensions in a systematic way. Superfield theories on a noncommutative superspace can be formulated in two folds, through the star product formalism and in terms of the supermatrices. We elaborate the duality between them by constructing the isomorphism explicitly and relating the superspace integrations of the star product Lagrangian or the superpotential to the traces of the supermatrices. We show there exists an interesting fine tuned commutative limit where the duality can be still maintained. Namely on the commutative superspace too, there exists a supermatrix model description for the superfield theory. We interpret the result in the context of the wave particle duality. The dual particles for the superfields in even and odd spacetime dimensions are D-instantons and D0-branes respectively to be consistent with the T-duality.

hep-th↗

Noncentral extension of the $AdS_{5} \times S^{5}$ superalgebra: supermultiplet of brane charges

We propose an extension of the su(2,2|4) superalgebra to incorporate the $F1/D1$ string charges in type IIB string theory on the $AdS_{5} \times S^{5}$ background, or the electro-magnetic charges in the dual super Yang-Mills theory. With the charges introduced, the superalgebra inevitably undergoes a noncentral extension, as noted recently in [1]. After developing a group theoretical method of obtaining the noncentral extension, we show that the charges form a certain nonunitary representation of the original unextended superalgebra, subject to some constraints. We solve the constraints completely and show that, apart from the su(2,2|4) generators, there exist 899 complex brane charges in the extended algebra. Explicitly we present all the super-commutators among them.

hep-th↗

Superfield formalism for the one loop effective action and CP(N) model in three dimensions

To obtain the one loop effective action for a given superfield theory, one encounters the notion such as the `supertrace' of a differential operator on superspace. We develop, in a systematic way for the superspace of arbitrary dimension, a method to determine the supertrace precisely. We present a formula to express the supertrace explicitly as the superspace integral, which enables us to write the one loop effective action within the superfield formalism and still maintain the manifest supersymmetry. In the second part of the paper, we apply the result to a three dimensional N=1 supersymmetric CP(N) model in the auxiliary superfield formalism. The model contains a novel topological interaction term. We show in the large N limit the one loop effective action is given by the supersymmetric Maxwell-Chern-Simons theory.

hep-th↗

3D N=2 massive super Yang-Mills and membranes/D2-branes in a curved background

We present a three dimensional novel massive N=2 super Yang-Mills action as a low energy effective worldvolume description of the D2-branes on a pp-wave. The action contains the Myers term, mass terms for three Higgs, and terms mixing the electric fields with other two Higgs. We derive the action in three different ways, from the M-theory matrix model, from the supermembrane action, and from the Dirac-Born-Infeld action. We verify the consistent mutual agreement and comment how each approach is complementary to another. In particular, we give the eleven dimensional geometric interpretation of the vacua in the worldvolume theory as the membranes tilted to the eleventh direction with the giant gravitons around.

hep-th↗

Description of identical particles via gauged matrix models : a generalization of the Calogero-Sutherland system

We elaborate the idea that the matrix models equipped with the gauge symmetry provide a natural framework to describe identical particles. After demonstrating the general prescription, we study an exactly solvable harmonic oscillator type gauged matrix model. The model gives a generalization of the Calogero-Sutherland system where the strength of the inverse square potential is not fixed but dynamical bounded by below.

hep-th↗

5D action for longitudinal five branes on a pp-wave

String modes in a pp-wave background are generically massive, and the worldvolume description of the branes is to be given by `massive' gauge theories. In this paper, we present a five dimensional super Yang-Mills action with the Kahler-Chern-Simons term plus the Myers term as a low energy worldvolume description of the longitudinal five branes in a maximally supersymmetric pp-wave background. We derive the action from the M-theory matrix model on the pp-wave. We utilize the previously found 4/32 BPS solution of rotating five branes with stacks of membranes, but, to obtain the static configuration, we reformulate the matrix model in a rotating coordinate system which provides the inertial frame for the branes. Expanding the matrix model around the solution, we first obtain a non-commutative field theory action naturally equipped with the full sixteen dynamical supersymmetries. In the commutative limit, we show only four supersymmetries survive, resulting in a novel five dimensional "N=1/2" theory.

hep-th↗

Supersymmetric objects in the M-theory on a pp-wave

We obtain, in a systematic way, all the classical BPS equations which correspond to the quantum BPS states in the M-theory on a fully supersymmetric pp-wave. The superalgebra of the M-theory matrix model shows that the BPS states always preserve pairs of supersymmetry, implying the possible fractions of the unbroken supersymmetry as 2/16, 4/16, 6/16,.... We study their classical counterparts, and find there are essentially one unique set of 2/16 BPS equations, three inequivalent types of 4/16 BPS equations, and three inequivalent types of 8/16 BPS equations only, in addition to the 16/16 static fuzzy sphere. We discuss various supersymmetric objects as solutions. In particular, when the fuzzy sphere rotates, the supersymmetry is further broken as 16/16 -> 8/16 -> 4/16.

hep-th↗

Superalgebra for M-theory on a pp-wave

We study the superalgebra of the M-theory on a fully supersymmetric pp-wave. We identify the algebra as the special unitary Lie superalgebra, su(2|4;2,0) or su(2|4;2,4), and analyze its root structure. We discuss the typical and atypical representations deriving the typicality condition explicitly in terms of the energy and other four quantum numbers. We classify the BPS multiplets preserving 4,8,12,16 real supercharges and obtain the corresponding spectrum. We show that in the BPS multiplet either the lowest energy floor is an su(2) singlet or the highest energy floor is an su(4) singlet.

hep-th↗